Work done through linear expansion

An 8000kg aluminum flagpole 100m long is heated by the sun from a temperature of 10°C to 20°C. Find the work done (in J) by the aluminum if the linear expansion coefficient is 24*10-6 /°C. (The density of aluminum is 2.7*103 kg/m3 and 1 atm = 1.0*105 N/m2)